A cost-effectiveness analysis of second-generation antihistamine 1 receptor blockers and Japanese kampo shoseiryuto for treatment of perennial allergic rhinitis in outpatient settings in Japan

Background: Perennial allergic rhinitis (PAR) is common in Japan. Second-generation antihistamines (SGAs) are used commonly for its treatment, but it remains unclear which SGA is the most cost-effective. Additionally, the pharmacoeconomics of Japanese kampo shoseiryuto, which has been traditionally prescribed to treat PAR in Japan, remain poorly understood.

Objectives: This study aimed to investigate the effectiveness of various SGAs and shoseiryuto for the treatment of PAR in Japanese outpatients, from the healthcare payer's perspective, using a base-case analysis.

Methods: The current study entailed identification of the most cost-effective of the six SGAs (bepotastine 10 mg, cetirizine 10 mg, ebastine 10 mg, epinastine 20 mg, loratadine 10 mg, and olopatadine 5 mg) and shoseiryuto, whose clinical effectiveness were evaluated using the overall improvement rate. The time horizon was 14 days. Costs were identified based on the Medical Fee Index in 2020.

Key findings: Overall, bepotastine 10 mg, cetirizine 10 mg, ebastine 10 mg, and loratadine 10 mg were found to be cost-effective. Shoseiryuto was less cost-effective than ebastine 10 mg (dominated). Ebastine 10 mg was found to be the most cost-effective based on deterministic and probabilistic sensitivity analyses.

Conclusions: Ebastine 10 mg was found to be the most cost-effective treatment strategy for PAR among the agents evaluated in this study. This insight might help in creating an appropriate formulary for the treatment of PAR in hospitals and communities.